Evict All-Projects after before reading it in a GitRefUpdate
The work on the project cache has surfaced an interesting
bug. Before this rework, the project cache was disabled in
tests, meaning every call to it would reload from disk.
Now, it is enabled.
This broke the SuperManifest tests because the plugin
listens to GitRefUpdated events on All-Projects,
refs/meta/config and keeps an internal state of parsed
configs. GitRefUpdated hooks are called before
ReceiveCommit evicts the project cache in #postUpdate.
This commit adds a band-aid to evict All-Projects before
reading the confing. This will only be triggered on
config updates to All-Projects. It means evicting
All-Projects twice on update.
Change-Id: I34def3f65bbead56462836e553ae03a0b4c79fa8